Methods of treating cellulite and subcutaneous adipose tissue

ABSTRACT

Embodiments of the present disclosure are directed to methods of inducing therapeutic adipose tissue inflammation using high frequency pressure waves (e.g. high frequency shockwaves) wherein the inflammation results in a reduction in the volume of subcutaneous adipose tissue. Embodiments include applying electrohydraulic generated shockwaves at a rate of between 10 Hz and 1000 Hz to reduce the appearance of cellulite or the volume of subcutaneous fat in a treatment area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 15/573,353, filedNov. 10, 2017, which is a national phase under 35 U.S.C. § 371 ofInternational Application PCT/US2016/032069, filed May 12, 2016, whichclaims priority to U.S. Provisional Patent Application No. 62/160,147,filed May 12, 2015; and U.S. Provisional Patent Application No.62/277,796, filed Jan. 12, 2016; the entire contents of each of whichare incorporated by reference in their respective entireties.

BACKGROUND 1. Field of the Invention

The present invention relates generally to methods of treatment forreducing adipose tissue using pressure waves. More particularly, but notby way of limitation, the present invention relates to methods oftreatment for reducing subcutaneous adipose tissue using shockwaves.

2. Description of Related Art Treating Celuite

Excess body fat, localized adiposity, and cellulite represent importantsocial problems. To date, techniques using radiofrequencies, ultrasound,and carbon dioxide have been studied as treatments for noninvasive bodycontouring.

Two high intensity ultrasound medical devices products that have beendeveloped for treatment of excess body fat include Ultrashape andLipoSonix. Ultrashape's technology, as disclosed in U.S. Pat. No.7,347,855 describes “[a] methodology and system for lysing adiposetissue including directing ultrasonic energy at a multiplicity of targetvolumes within the region, which target volumes contain adipose tissue,thereby to selectively lyse the adipose tissue in the target volumes andgenerally not lyse non-adipose tissue in the target volumes andcomputerized tracking of the multiplicity of target volumesnotwithstanding movement of the body.” “In accordance with a preferredembodiment of the present invention, the modulating provides between 2and 1000 sequential cycles at an amplitude above a cavitation threshold,more preferably between 25 and 500 sequential cycles at an amplitudeabove a cavitation threshold and most preferably between 100 and 300sequential cycles at an amplitude above a cavitation threshold.”

Liposonix's technology, as disclosed in U.S. Pat. No. 7,258,674,describes “a system for the destruction of adipose tissue utilizing highintensity focused ultrasound (HIFU) within a patient's body.”Liposonix's high intensity focused ultrasound technology can causethermal damage of the adipose tissue at focused spots within the adiposetissue.

While both technologies result in adipose tissue destruction, theapplication of these technologies is likely to have potential safetyissues because of the cavitation or thermal affects. These cavitation orthermal affects may even cause damage to non-adipose cells and tissues.Given these safety issues, great care must be taken in treating apatient using these technologies.

An approach to fat tissue volume reduction, that minimizes the safetyissues related to these high intensity ultrasound technologies, iscryolipolysis. As the name implies, cryolipolysis is a medical treatmentto reshape body contours that relies on controlled cooling of thepatient's tissue to cause a non-invasive local reduction of fatdeposits. This technology has been commercialized by Zeltiq under thename CoolSculpting and is described in U.S. Pat. No. 8,840,608,entitled, “Methods and devices for selective disruption of fatty tissueby controlled cooling” As described in this patent, the “inventionrelates to methods for use in the selective disruption of lipid-richcells by controlled cooling.”

While the process is not fully understood, it appears fatty tissue thatis cooled below body temperature, but above freezing, undergoeslocalized cell death followed by a local adipose inflammatory response.This inflammation, over the course of several months, results in areduction of the fatty tissue layer. See Manstein et al. Specifically,as discussed by Krueger N, et al.: “cryolipolysis exploits the premisethat adipocytes are more susceptible to cooling than other skin cells.”“Precise application of cold temperatures triggers the death ofadipocytes that are subsequently engulfed and digested by macrophages.”“An inflammatory process stimulated by apoptosis of adipocytes, asreflected by an influx of inflammatory cells, can be seen within 3 daysafter treatment and peaks at approximately 14 days thereafter asadipocytes become surrounded by his histiocytes, neutrophils,lymphocytes, and other mononuclear cells.”

In terms of efficacy, cryolipolysis has demonstrated reducing adiposetissue by 20-30% in published studies. More importantly, compared toultrasound technologies based on cavitation or thermal mechanism ofaction to reduce adipose volume, cryolipolysis is relatively safe.According to Zelteq's company website. “the controlled cooling of theCoolSculpting procedure targets and eliminates only fat cells. Othertreatment modalities, such as lasers, radiofrequency and focusedultrasound, affect fat cells and may affect other adjacent tissue in away that is not comparable to the CoolSculpting method ofCryolipolysis®.” While side effects such as transient local redness,bruising and numbness of the skin are common following the cryolipolysistreatment, the company claims the these side effects typically subsideover time.

While the use of cryolipolysis to induce an inflammatory response thatresults in an adipose tissue volume reduction is an improvement overprior art approaches, it is still less than ideal.

One problem with using cryolipolysis to induce inflammation is the timeit takes to administer the cryolipolysis treatment (i.e., cooling theadipose tissue). Typically, the cryolipolysis procedure (e.g. usingCoolsculpting) lasts approximately 1-2 hours for each treatment site(e.g., right or left love handle). If a patient seeking to have fatvolume reduction in an extensive area, the patient would be required tohave multiple 1-2 hour cryolipolysis treatments that could requiremultiple doctor visits. Another problem, during these long cryolipolysistreatments, the patient is limited on making any movements, which makesthe treatment unpleasant. Additionally, a major problem for thephysician or spa owner who is treating the patient, the required longtreatments limits the throughput of patients that can be seen which hasa real impact on the practice revenues.

Approaches to improve cryolipolysis, by use of ultrasound, have beenreported. US Patent Application No. 2013/0190744 by Anderson R R, one onthe primary inventors of cryolipolysis, discloses, “cooling of thelipid-rich tissue can be accompanied by mechanical or other disruptionof the fatty tissue. e.g., through application of acoustic fields thatmay be either constant or oscillating in time. For example, one or moretransducers may be introduced into the region of tissue being cooledthrough the catheter, and signals provided to them to produce mechanicaloscillations and disruption of the fatty tissue.” “Alternatively,ultrasound energy can be provided from one or more sources of suchenergy, e.g., piezoelectric transducers, provided in contact with anouter surface of the subject's body during the cooling procedure. Suchultrasound energy can optionally be focused to the approximate depth ofthe fatty tissue being cooled to further disrupt the tissue.”

Another group, lead by Ferraro GA, studied synergistic effects ofcryolipolysis and shockwaves for noninvasive body contouring. Thistechnology developed by the Promoitalia Group SP and called Ice-ShockLipolysis, “is a new noninvasive procedure for reducing subcutaneous fatvolume and fibrous cellulite in areas that normally would be treated byliposuction.” Ice-Shock Lipolysis “uses a combination of acoustic wavesand cryolipolysis. Shockwaves are focused on the collagen structure ofcellulite-afflicted skin. When used on the skin and underlying fat, theycause a remodeling of the collagen fibers, improving the orange-peelappearance typical of the condition. Cryolipolysis, on the other hand,is a noninvasive method used for the localized destruction ofsubcutaneous adipocytes, with no effects on lipid or liver marker levelsin the bloodstream. The combination of the two procedures causes theprogrammed death and slow resorption of destroyed adipocytes.”

The combination of cryolipolysis and acoustic waves promises to improvethe outcome of the cryolipolysis procedure. As discussed in the priorart, the use of the acoustic waves are to either aid in the directdisruption of the adipose cell or to provide better appearance outcomesby remodeling the collagen fibers. However, the principal method ofinducing inflammation, which leads to the adipose tissue volumereduction, is from the cooling of the adipose tissue. As a result, thefundamental problems, as discussed above, related to the cryolipolysistreatment has not changed.

SUMMARY

Embodiments of the present disclosure are directed to methods ofinducing therapeutic adipose tissue inflammation using high frequencypressure waves (e.g. high frequency shockwaves) wherein the inflammationresults in a reduction in the volume of subcutaneous adipose tissue. Insome embodiments, the high frequency pressure waves (e.g., in the formof shockwaves) are applied to the skin so as to induce lipid nucleation,which can cause crystallization and eventually, adipocyte apoptosis.Adipocyte apoptosis can result in a reduction in the appearance of thecellulite on the skin (e.g., smoother skin) overlying the treatedadipocyte tissue. In some embodiments, the applied pressure waves areapplied at a rate and magnitude such that minimal to no cavitationoccurs in the tissue. In some embodiments, the methods of treatment canreduce undesired side effects and the total times per treatment (TTPT)relative to known systems. Moreover, the present pressure wave therapiescan be used to induce inflammation across a given area of adipose tissuesuch that a practical total time per treatment (TTPT) can be obtained.

Present embodiments include methods that comprise: generating aplurality of pressure waves at sub-cavitation levels and delivering atleast a portion of the plurality of pressure waves to an adipose tissuethereby inducing inflammation in the adipose tissue. It is noted thatthroughout the application, pressure waves are understood to includeshockwaves.

Some embodiments include methods that comprise: generating a pluralityof pressure waves at a pulse rate of at least 10 Hz and delivering to anadipose tissue at least a portion of the plurality of pressure waves.

Some embodiments include methods of applying electrohydraulic generatedshockwaves to induce inflammation in an adipose tissue. The EH-shockwavesystems utilized can be configured to deliver shockwaves to tissues toinduce inflammation on the treated tissue, such as by deliveringshockwaves at higher frequencies (e.g., greater than ˜10 Hz).

Still other embodiments also include methods of generating pressure waveenergy of at least 0.5 mJ per mm² at the pressure wave outlet window anddelivering to an adipose tissue at least a portion of the plurality ofpressure waves. In further embodiments, the pressure wave energy of atleast 0.5 mJ per mm² at the pressure wave outlet window is applied to atleast a 20 mm² area. In some embodiments, at least a portion of thegenerated pressure waves are planar or unfocused.

Some embodiments include a method of treating a patient to reducesubcutaneous fat in a treatment area. The fat comprises fat cells havingintracellular fat and interstitial space between the fat cells. Themethod can comprise directing a pressure wave generating probe to exposean external area of the patient to a series of pressure waves, where thepressure wave generating probe comprises a pressure wave outlet window,where the pressure wave generating probe emits at least 0.5 mJ per mm²at the pressure wave outlet window, and where the pressure waves are notfocused prior to entering into the treatment area of the patient.

Some embodiments include a method of inducing inflammation ofsubcutaneous adipose tissue. The method can comprise directing apressure wave generating probe to expose an external area of the patientto a series of pressure waves, where the pressure wave generating probecomprises a pressure wave outlet window and where the pressure wavegenerating probe emits at least 0.5 mJ per mm² of the pressure waveoutlet window.

Some embodiments include a method of applying pressure wave energy to anadipose tissue. The method can comprise directing a pressure wavegenerating probe to expose an external area of the patient to a seriesof pressure waves, where the pressure wave generating probe comprises apressure wave outlet window and where the pressure wave generating probeemits at least 0.5 mJ per mm² of the pressure wave outlet window.

Some embodiments include a method of treating a patient to reduce theappearance of cellulite in a treatment area. The method can comprisedirecting a pressure wave generating probe to expose an external area ofthe patient to a series of pressure waves, where the pressure wavegenerating probe comprises a pressure wave outlet window and where thepressure wave generating probe emits at least 0.5 mJ per mm² of thepressure wave outlet window.

Some embodiments include a method of inducing inflammation insubcutaneous adipose tissue. The method can comprise directing apressure wave generating probe to expose an external area of the patientto a series of pressure waves, where the pressure wave generating probecomprises a pressure wave outlet window and where the probe is emits aseries of pressure waves that would not induce transient cavitationbubbles in an aqueous solution.

Some embodiments include a method where the probe emits a series ofpressure waves that would induce minimal to no adipose cell damage whiletreating an external treatment area of a subject, e.g., a patient oranimal model. For example, in some embodiments, the probe emits a seriesof pressure waves that would increase the amount of lipid crystalswithin an adipose tissue within the treatment area of the subject ascompared with an adipose tissue sample outside of the treatment area ofthe subject. In some embodiments, the probe can emit a series ofpressure waves that would cause a comparable increase of a luminosityvalue of an adipose tissue sample from the treated area relative to thatof an adipose tissue sample from an untreated area of the subject. Instill other embodiments, the probe emits a series of pressure waves thatwould cause a comparable volume loss of a treatment area relative to anuntreated area of the subject.

The term “coupled” is defined as connected, although not necessarilydirectly, and not necessarily mechanically; two items that are “coupled”may be unitary with each other. The terms “a” and “an” are defined asone or more unless this disclosure explicitly requires otherwise. Theterm “substantially” is defined as largely but not necessarily whollywhat is specified (and includes what is specified; e.g., substantially90 degrees includes 90 degrees and substantially parallel includesparallel), as understood by a person of ordinary skill in the art. Inany disclosed embodiment, the terms “substantially,” “approximately,”and “about” may be substituted with “within [a percentage] of” what isspecified, where the percentage includes 0.1, 1, 5, and 10 percent.

The terms “comprise” (and any form of comprise, such as “comprises” and“comprising”), “have” (and any form of have, such as “has” and“having”), “include” (and any form of include, such as “includes” and“including”) and “contain” (and any form of contain, such as “contains”and “containing”) are open-ended linking verbs. As a result, a system orapparatus that “comprises,” “has,” “includes” or “contains” one or moreelements possesses those one or more elements, but is not limited topossessing only those elements. Likewise, a method that “comprises,”“has,” “includes” or “contains” one or more steps possesses those one ormore steps, but is not limited to possessing only those one or moresteps.

Any embodiment of any of the present systems, apparatuses, and methodscan consist of or consist essentially of—rather thancomprise/include/contain/have—any of the described steps, elements,and/or features. Thus, in any of the claims, the term “consisting of” or“consisting essentially of” can be substituted for any of the open-endedlinking verbs recited above, in order to change the scope of a givenclaim from what it would otherwise be using the open-ended linking verb.

Further, a structure (e.g., a component of an apparatus) that isconfigured in a certain way is configured in at least that way, but itcan also be configured in other ways than those specifically described.

Details associated with the embodiments described above and others arepresented below.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings illustrate by way of example and not limitation.For the sake of brevity and clarity, every feature of a given structureis not always labeled in every figure in which that structure appears.Identical reference numbers do not necessarily indicate an identicalstructure. Rather, the same reference number may be used to indicate asimilar feature or a feature with similar functionality, as maynon-identical reference numbers. The figures are drawn to scale (unlessotherwise noted), meaning the sizes of the depicted elements areaccurate relative to each other for at least the embodiment depicted inthe figures.

FIG. 1 depicts a waveform that can be emitted by system of FIG. 3 and/orthe handheld probe of FIG. 4 into target tissue.

FIG. 2 depicts a conceptual flowchart of one embodiment of the presentmethods.

FIG. 3 depicts a block diagram of a first embodiment of the presentelectro-hydraulic (EH) shockwave generating systems.

FIG. 4 depicts a cross-sectional side view of a handheld probe for someembodiments of the present EH shockwave generating systems.

FIG. 4A depicts a cross-sectional side view of a first embodiment of aremovable spark head usable with embodiments of the present handheldprobes, such as the one of FIG. 4.

FIG. 4B depicts a cutaway side view of a second embodiment of aremovable spark head usable with embodiments of the present handheldprobes, such as the one of FIG. 4.

FIG. 4C depicts a cutaway side view of a third embodiment of a removablespark head usable with embodiments of the present handheld probes, suchas the one of FIG. 4.

FIGS. 5A-5B depict a timing diagrams of one example of the timedapplication of energy cycles or voltage pulses in the system of FIG. 3and/or the handheld probe of FIG. 4.

FIG. 6 depicts a schematic diagram of one embodiment of a multi-gappulse-generation system for use in or with some embodiments of thepresent systems.

FIG. 7 depicts a block diagram of an embodiment of a radio-frequency(RF) powered acoustic ablation system.

FIGS. 8A-8B depict perspective and cross-sectional views of a firstembodiment of a spark chamber housing.

FIG. 9 depicts a cross-sectional view of a second embodiment of sparkchamber housing.

FIG. 10 depicts a schematic diagram of an electric circuit for apulse-generation system.

FIG. 11 depicts an exploded perspective view of a further embodiment ofthe present probes having a spark head or module.

FIGS. 12A and 12B depict parts of the assembly of the probe of FIG. 11.

FIGS. 13A and 13B depict perspective and side cross-sectional views,respectively, of the probe of FIG. 11.

FIG. 13C depicts an enlarged side cross-sectional view of a spark gap ofthe probe of FIG. 11.

FIG. 14 depicts a schematic diagram of a second embodiment of anelectric circuit for a prototyped pulse-generation system.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Embodiments of the present disclosure are directed to inducinginflammation in a tissue and particularly a tissue near the surface ofthe skin such as a subcutaneous adipose tissue, by applying a pluralityof shockwaves to the tissue. The induced inflammation will lead toeventual apoptosis to a portion of the cells in the treated area. Whilethe shockwave treatments induce inflammation, the shockwaves are at astrength, frequency, and duration that are not likely to causecavitation or thermal degradation in the treated tissue. As such, cellrupturing, would not be likely to occur. Rather, apoptosis would becaused by the inflammatory response of the body.

When the cell is exposed to repeated pressure waves within a certainfrequency and energy level, sub-lytic injury occurs that inducesinflammation. More particularly, the repeated high frequency, pressurewave energy applied to cells with lipid reserves can cause sub-lyticinjury to the lipid containing vacuoles, triggering an inflammatoryresponse. The ability to induce inflammation is dependent on fourfactors: (1) applied intensity (Pa), (2) the rate of wave pulses (Hz),(3) wave form shape (e.g., wave front rise time (ns) and wave length(ns)), or (4) duration of exposure. One or more of these factors can bemanipulated to cause a tissue with a high amount of stored lipids tohave increased inflammation as compared to a non-treated area of similarcharacter. The inflammation will eventually result in apoptosis and areduction in the number of cells in the treated area.

A possible theory to explain the phenomenon of the induced inflammationsis the formation of lipid crystals in a sub-cellular structure. In aliquid lipid media, such as in adipose cells, a series of pressure wavesat a high frequency may induce nucleation of lipid crystals leading tothe formation of crystals sufficiently large to cause injury to cellularorganelles, such as a bilayer membrane. This injury initiates aninflammatory response that will eventually lead to apoptosis andnecrosis. Nearby cells that are also exposed but not lipid rich likeadipocyte cells, such as cells in the epidermis layer, are less likelyto be damaged in the process.

In some embodiments, a method of treating a patient to reducesubcutaneous fat in a treatment area can comprise: directing a pressurewave generating probe (such as probe 38 or 38 a described below) toexpose an external area of the patient to a series of pressure waves,where the pressure wave generating probe comprises a pressure waveoutlet window, where the pressure wave generating probe is configured togenerate at least 0.5 mJ per mm² or at least 2 mJ per mm² at thepressure wave outlet window. For example, the pressure waves can have0.5, 0.6, 0.8, 0.9, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3,3.4, 3.8, 4, 4.4, 4.8, 5, 5.5, 6, 6.5, 7 mJ per mm², or any value orrange therebetween. In some embodiments, the pressure wave generatingprobe is configured to generate or generates between 0.5 mJ per mm² to 5mJ per mm². In some embodiments, the pressure wave outlet window has anarea of 0.5 cm² to 20 cm². For example, the outlet window can have anarea of at least 0.5, 0.8, 1, 2, 3, 4, 5, 6, 7. 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20 cm², or any value or range therebetween.

In some embodiment, the pressure waves are unfocused or substantiallyplanar prior to entering into the treatment area of the patient. Otherembodiments of the present methods comprise focusing the one or morepressure waves to a treatment area. In some embodiments the adiposetissue at which the one or more pressure waves is focused is the depthat which there is adipose tissue. Focusing the shockwaves may result inhigher pressures at targeted cells than unfocused or planar waves.

In some embodiments, the treatment area is a portion of butt, thigh,stomach, waist, and/or upper arm area. In some embodiments, thetreatment area of subcutaneous fat is within a depth of 0-6 cm from theexternal area, such as 1, 2, 3, 4, 5, 6 cm, or any value or rangetherebetween. In some embodiments, the treatment area is at a depth of1-4 cm.

In some embodiments, the pressure wave directed to the treatment area isa shockwave. FIG. 1 depicts a waveform of a shockwave that can beemitted from a probe and into a volume of tissue. The depicted form canbe useful for inducing inflammation without causing cell rupturing.Pulse 300 is of a typical shape for an impulse generated by thedescribed electrohydraulic (EH) spark heads described below. Forexample, pulse 300 has a rapid rise time (or wave front rise time), ashort duration, and a ring down period. The units of vertical axis V_(a)are arbitrary as may be displayed on an oscilloscope.

In some embodiments, the pressure wave generating probe can emit ashockwave comprising the following waveform characteristics in atransmitting medium. A transmitting medium can be a gas (e.g., air), atissue (e.g., an adipose tissue) or an aqueous solution (e.g., a salinesolution, such as one at 0.5-10% concentration). In some embodiments, ashockwave emitted at the outlet window of the probe and/or delivered tothe treatment area can have a shockwave front rise time of less than 20ns, less than 18 ns, less than 15 ns, or less than 12 ns as measured ina transmitting medium. In some embodiments, the actual acoustic pulseamplitude emitted may be 0.5 to 50 MPa. In some embodiments, theindividual time periods 304 may be 0.5 to 50 micro-seconds each in atransmitting medium. In some embodiments, the probe emits a pressurewave at a pulse rate of at least 10 Hz. For example, the probe emits apressure wave at a pulse rate of between 10 Hz and 1000 Hz., such as 20,30, 40, 50, 60, 70, 80 90, 100, 150, 200, 250, 300, 350, 400, 450, 500,550, 600, 650, 700, 750, 800, 850, 900, 950, 1000 Hz, or any value orrange therebetween. In some embodiments, the probe emits a pressure waveat a pulse rate of between 10 Hz and 100 Hz. In some embodiments, theprobe emits a pressure wave at a pulse rate of between 20 Hz and 75 Hz.In some embodiments, the probe emits a pressure wave at a pulse rate ofbetween 100 Hz and 500 Hz. In some embodiments, the probe emits apressure wave at a pulse rate of between 500 Hz and 1000 Hz. In someembodiments, the emitted waves are configured according to thecharacteristics above to induce minimal to no detectable transientcavitation in a transmitting medium.

In some embodiments, the method of treatment induces lipidcrystallization, induces inflammation in the treated adipose tissue,reduces the amount of subcutaneous fat in the treatment area, and/orreduces the appearance of cellulite (e.g., resulting in a smootherappearance in the skin overlying the treatment area). In someembodiments, subcutaneous fat comprises fat cells having intracellularfat and interstitial space between the fat cells. A reduction in theamount of fat (e.g., a reduction in volume) can be determined by ahistological evaluation or 3-D camera. Example 2 describes a method fordetecting a change in adipose tissue volume. In some embodiments, theamount of fat is reduced about 1-14 days after one or more treatments,such as after 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 days afterthe last treatment, or any value or range therebetween. In someembodiments, an inflammation increase is indicated by an increase of oneor more cytokines, such as one or more of leptin, IL-6, and TNF-α, inthe patient's blood serum, or in the treatment area after treatment. Insome embodiments, an inflammation increase is indicated by an increasein inflammatory cells in the treatment area after treatment. In someembodiments, even with an inflammation increase, the series of pressurewaves would induce minimal to no adipose cell rupturing immediatelyafter treatment, such as when treating an external treatment area of ananimal model. Cell rupturing can be detected histologically, such asunder 200× to 1000× magnification. In some embodiments, inducing lipidcrystallization is indicated by relatively higher tissue luminosityvalue under cross-polarized microscopy as compared with a controlsample. Example 3 describes a method for detecting a comparable increasein lipid crystallization. Because of the recognized difficulty ofperforming such evaluations on a human patient, in some embodiments, theresult of a treatment on a human can be estimated to correspond to theresult of a treatment protocol on an animal model, such as a minipig.

Inducing crystallization of lipids using the methods of this inventioncan occur in relatively short treatment times. As a result, the longtreatment times seen with the prior art, along with the problemsassociated with these long treatment times (e.g., office space, costs,discomfort, etc.) can be avoided using this invention. For example, insome embodiments, a treatment session can be 1 to 30 minutes within a 24hour period. A treatment session can be 1, 2, 4, 5, 8, 10, 12, 15, 18,20, 22, 24, 26, 28, 30 minutes or any value or within any rangetherebetween. A treatment session can be performed daily, every otherday, every three days, weekly, bi-weekly, monthly, bi-monthly, andquarterly. A treatment plan can comprise 1 to 20 sessions within aone-year period, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20 sessions or any value therebetween. In someembodiments, a treatment plan comprises a session at least once per twoweeks for at least 6 weeks.

FIG. 2 illustrates one embodiment of a method 700 to direct shockwavesto target tissue. In the embodiment shown, method 700 comprises a step704 in which a treatment area 712 is identified. For example, treatmentarea 712 can comprise skin affected with cellulite or having an unwantedaccumulation of subcutaneous fat. In the embodiment shown, method 700also comprises a step 716 in which a probe or handpiece 38 is disposedtoward treatment area 712, such that shockwaves originating in probe 38can be directed toward the adipose tissue in the treatment area. In theembodiment shown, method 700 also comprises a step 720 in which apulse-generation system 26 is coupled to probe 38. In the embodimentshown, method 700 also comprises a step 724 in which pulse-generationsystem 26 is activated to generate sparks across electrodes within probe38 to generate shockwaves in probe 38 for delivery to adipose tissueunderlying treatment area 712, as shown.

Shockwave Generator

The above-described modalities may employ a shockwave generator. Thegenerator can be configured to deliver focused, defocused, or planarwaves with the above-described characteristics. In some embodiments, EHwaves are generated. For example, the systems and apparatus described inU.S. Patent Publication No. 2014/0257144 can be configured to apply EHshockwaves at the described rate, energy level, and duration. Inparticular, the shockwave generating apparatus can be configured togenerate a planar or defocused pressure wavefront.

With reference to FIG. 3, such a system can include a handheld probe(e.g., with a first housing, such as in FIG. 4) and a separatecontroller or pulse-generation system (e.g., in or with a second housingcoupled to the handheld probe via a flexible cable or the like). In theembodiment shown, apparatus 10 comprises: a housing 14 defining achamber 18 and a shockwave outlet 20; a liquid (54) disposed in chamber18; a plurality of electrodes (e.g., in spark head or module 22)configured to be disposed in the chamber to define one or more sparkgaps; and a pulse-generation system 26 configured to apply voltagepulses to the electrodes at a rate of between 10 Hz and 1000 Hz, such asbetween 10 Hz and 100 Hz, 100 Hz and 500 Hz, or 500 Hz and 1000 Hz. Inthis embodiment, the pulse-generation system 26 is configured to applythe voltage pulses to the electrodes such that portions of the liquidare vaporized to propagate shockwaves through the liquid and theshockwave outlet window.

In the embodiment shown, pulse-generation system 26 is configured foruse with an alternating current power source (e.g., a wall plug). Forexample, in this embodiment, pulse-generation system 26 comprises a plug30 configured to be inserted into a 110V wall plug. In the embodimentshown, pulse-generation system 26 comprises a capacitive/inductive coilsystem, on example of which is described below with reference to FIG. 7.In the embodiment shown, pulse-generation system 26 is (e.g., removably)coupled to the electrodes in spark head or module 22 via a high-voltagecable 34, which may, for example, include two or more electricalconductors and/or be heavily shielded with rubber or other type ofelectrically insulating material to prevent shock. In some embodiments,high-voltage cable 34 is a combined tether or cable that furtherincludes one or more (e.g., two) liquid lumens through which chamber 18can be filled with liquid and/or via which liquid can be circulatedthrough chamber 18 (e.g., via combined connection 36). In the embodimentshown, apparatus 10 comprises a handheld probe or handpiece 38 and cable34 is removably coupled to probe 38 via a high-voltage connector 42,which is coupled to spark head or module 22 via two or more electricalconductors 44. In the embodiment shown, probe 38 comprises a head 46 anda handle 50, and probe 38 can comprise a polymer or other electricallyinsulating material to enable an operator to grasp handle 50 to positionprobe 38 during operation. For example, handle 50 can be molded withplastic and/or can be coated with an electrically insulating materialsuch as rubber.

In the embodiment shown, a liquid 54 (e.g., a dielectric liquid such asdistilled water) is disposed in (e.g., and substantially fills) chamber18. In this embodiment, spark head 22 is positioned in chamber 18 andsurrounded by the liquid such that the electrodes can receive voltagepulses from pulse-generation system 26 (e.g., at a rate of between 10 Hzand 1000 Hz, 10 Hz and 100 Hz, 100 Hz and 500 Hz, or 500 Hz and 1000 Hz)such that portions of the liquid are vaporized to propagate shockwavesthrough the liquid and shockwave outlet 20. In the embodiment shown,probe 38 includes an acoustic delay chamber 58 between chamber 18 andoutlet 20. In this embodiment, acoustic delay chamber is substantiallyfilled with a liquid 62 (e.g., of the same type as liquid 54) and has alength 66 that is sufficient to permit shockwaves to form and/or bedirected toward outlet 20. In some embodiments, length 66 may be between2 millimeters (mm) and 25 millimeters (mm). In the embodiment shown,chamber 18 and acoustic-delay chamber 58 are separated by a layer ofsonolucent (acoustically permeable or transmissive) material thatpermits pressure waves or, more particularly, shockwaves to travel fromchamber 18 into acoustic-delay chamber 58. In other embodiments, liquid62 may be different than liquid 54 (e.g., liquid 62 may comprisebubbles, water, oil, mineral oil, and/or the like). Certain featuressuch as bubbles may introduce and/or improve a nonlinearity in theacoustic behavior of liquid 54 to increase the formation of shockwaves.In further embodiments, chamber 18 and acoustic-delay chamber 58 may beunitary (i.e., may comprise a single chamber). In further embodiments,acoustic-delay chamber 58 may be replaced with a solid member (e.g., asolid cylinder of elastomeric material such as polyurethane). In theembodiment shown, probe 38 further includes an outlet member 70removably coupled to the housing at a distal end of the acoustic delaychamber, as shown. Member 70 is configured to contact an external arealocated above tissue 74, and can be removed and either sterilized orreplaced between patients. Member 70 comprises a polymer or othermaterial (e.g., low-density polyethylene or silicone rubber) that isacoustically permeable to permit shockwaves to exit acoustic-delaychamber 58 via outlet 20. In some embodiments, an acoustic coupling gel(not shown) may be disposed between member 70 and tissue 74 to lubricateand provide additional acoustic transmission into tissue 74.

In the embodiment shown, probe 38 includes an acoustic mirror 78 thatcomprises a material (e.g., glass) and is configured to reflect amajority of sound waves and/or shockwaves that are incident on theacoustic mirror. As shown, acoustic mirror 78 can be angled to reflectsound waves and/or shockwaves (e.g., that originate at spark head 22)toward outlet 20 (via acoustic-delay chamber) in a defocused manner. Inthe embodiment shown, housing 14 can comprise a translucent ortransparent window 82 that is configured to permit a user to view(through window 82, chamber 18, chamber 58, and member 70) a region of apatient (e.g., tissue 74) comprising target cells (e.g., duringapplication of shockwaves or prior to application of shockwaves toposition outlet 20 at the target tissue). In the embodiment shown,window 82 comprises an acoustically reflective material (e.g., glass)that is configured to reflect a majority of sound waves and/orshockwaves that are incident on the window. For example, window 82 cancomprise clear glass of sufficient thickness and strength to withstandthe high-energy acoustic pulses produced at spark head 22 (e.g.,tempered plate glass having a thickness of about 2 mm and an opticaltransmission efficiency of greater than 50%).

In FIG. 3, a human eye 86 indicates a user viewing the target tissuethrough window 82, but it should be understood that target tissue may be“viewed” through window 82 via a camera (e.g., a digital still and/orvideo camera). By direct or indirect observation, acoustic energy can bepositioned, applied, and repositioned according to target tissues, suchas a region of cellulite, and by indications of acoustic energy, such asa change in the color of the tissue.

FIG. 4 depicts a cross-sectional side view of a second embodiment 38 aof the present handheld probes or handpiece for use with someembodiments of the present EH shockwave generating systems andapparatuses. Probe 38 a is substantially similar in some respects toprobe 38, and the differences are therefore primarily described here.For example, probe 38 a is also configured such that the plurality ofelectrodes of spark head 22 a are not visible to a user viewing a region(e.g., of target tissue) through window 82 a and outlet 20 a. However,rather than including an optical shield, probe 38 a is configured suchthat spark head 22 a (and the electrodes of the spark head) are offsetfrom an optical path extending through window 82 a and outlet 20 a. Inthis embodiment, acoustic mirror 78 a is positioned between spark head22 a and outlet 20 a, as shown, to define a boundary of chamber 18 a andto direct acoustic waves and/or shockwaves from spark head 22 a tooutlet 20 a. In the embodiment shown, window 82 a can comprise a polymeror other acoustically permeable or transmissive material becauseacoustic mirror 78 a is disposed between window 82 a and chamber 18 aand sound waves and/or shockwaves are not directly incident on window 82a (i.e., because the sound waves and/or shockwaves are primarilyreflected by acoustic mirror 78 a).

In the embodiment shown, spark head 22 a includes a plurality ofelectrodes 100 that define a plurality of spark gaps. The use ofmultiple spark gaps can be advantageous because it can double the numberof pulses that can be delivered in a given period of time. For example,after a pulse vaporizes an amount of liquid in a spark gap the vapormust either return to its liquid state or must be displaced by adifferent portion of the liquid that is still in a liquid state. Inaddition to the time required for the spark gap to be re-filled withwater before a subsequent pulse can vaporize additional liquid, sparksalso heat the electrodes. As such, for a given spark rate, increasingthe number of spark gaps reduces the rate at which each spark gap mustbe fired and thereby extends the life of the electrodes. Thus, ten sparkgaps potentially increases the possible pulse rate and/or electrode lifeby a factor of ten.

As noted above, high pulse rates can generate large amounts of heat thatmay increase fatigue on the electrodes and/or increase the timenecessary for vapor to return to the liquid state after it is vaporized.In some embodiments, this heat can be managed by circulating liquidaround the spark head. For example, in the embodiment of FIG. 4, probe38 includes conduits 104 and 108 extending from chamber 18 a torespective connectors 112 and 116, as shown. In this embodiment,connectors 112 and 116 can be coupled to a pump to circulate liquidthrough chamber 18 a (e.g., and through a heat exchanger. For example,in some embodiments, pulse-generation system 26 (FIG. 3) can comprise apump and a heat exchanger in series and configured to be coupled toconnectors 112 and 116 via conduits or the like. In some embodiments, afilter can be included in probe 38 a, in a spark generation system(e.g., 26), and/or between the probe and the spark generation system tofilter liquid that is circulated through the chamber

As illustrated in FIG. 4, application of each shockwave to a targettissue includes a wave front 118 propagating from outlet 20 a andtraveling outward through tissue 74. As shown, wave front 118 is curvedaccording to its expansion as it moves outwardly and partially accordingto the shape of the outer surface of outlet member 70 a that contactstissue 74. In other embodiments, such as that of FIG. 3, the outer shapeof the contact member can be planar.

FIG. 4A depicts an enlarged cross-sectional view of first embodiment ofa removable spark head, shown as module 22 a. In the embodiment shown,spark head 22 a comprises a sidewall 120 defining a spark chamber 124,and a plurality of electrodes 100 a, 100 b, 100 c disposed in the sparkchamber. In the embodiment shown, spark chamber 124 is filled withliquid 128 which may be similar to liquid 54 (FIG. 3). At least aportion of sidewall 120 comprises an acoustically permeable ortransmissive material (e.g., a polymer such as polyethylene) configuredto permit sound waves and/or shockwaves generated at the electrodes totravel through sidewall 120 and through chamber 18 a (FIG. 4). Forexample, in the embodiment shown, spark head 22 a includes a cup-shapedmember 132 that may be configured to be acoustically reflective andincludes an acoustically permeable cap member 136. In this embodiment,cap member 136 is dome shaped to approximate the curved shape of anexpanding wavefront that originates at the electrodes and to compressthe skin when applied with moderate pressure. Cap member 136 can becoupled to cup-shaped member 132 with an O-ring or gasket 140 and aretaining collar 144. In the embodiment shown, cup-shaped member 132 hasa cylindrical shape with a circular cross-section (e.g., with a diameterof 2 inches or less). In this embodiment, cup-shaped member includesbayonet-style pins 148, 152 configured to align with correspondinggrooves in head 46 a of probe 38 a (FIG. 4) to lock the position ofspark head 22 a relative to the probe.

In the embodiment shown, an electrode core 156 having conductors 160 a,160 b, 160 c and extending through aperture 164, with the interfacebetween aperture 164 and electrode core 156 sealed with a grommet 168.In the embodiment shown, a central conductor 160 a extends through thecenter of core 156 and serves as a ground to corresponding centerelectrode 100 a. Peripheral conductors 160 b, 160 c are in communicationwith peripheral electrodes 100 b, 100 c to generate sparks across thespark gap between electrodes 100 a and 100 b, and between electrodes 100a and 100 c. It should be understood that while two spark gaps areshown, any number of spark gaps may be used, and may be limited only bythe spacing and size of the spark gaps. For example, other embodimentsinclude 3, 4, 5, 6, 7, 8, 9, 10, or even more spark gaps.

FIG. 4B depicts an enlarged cutaway side view of a second embodiment ofa removable spark head or module 22 b. In the embodiment shown, sparkhead or module 22 b comprises a sidewall 120 a defining a spark chamber124 a, and a plurality of electrodes 100 d-1, 100 d-2, 100, 100 fdisposed in the spark chamber. In the embodiment shown, spark chamber124 a is filled with liquid 128 a which may be similar to liquid 128and/or 54. At least a portion of sidewall 120 a comprises anacoustically permeable or transmissive material (e.g., a polymer such aspolyethylene) configured to permit sound waves and/or shockwavesgenerated at the electrodes to travel through sidewall 120 a and throughchamber 18 a (FIG. 4). For example, in the embodiment shown, spark head22 b includes a cup-shaped member 132 a that may be configured to beacoustically reflective and an acoustically permeable cap member 136 a.In this embodiment, cap member 136 a is dome shaped to approximate thecurved shape of an expanding wavefront that originates at the electrodesand to compress the skin when applied with moderate pressure. Cap member136 a can be coupled to cup-shaped member 132 a with an O-ring or gasket(not shown, but similar to 140) and a retaining collar 144 a. In theembodiment shown, cup-shaped member 132 a has a cylindrical shape with acircular cross-section (e.g., with a diameter of 2 inches or less). Insome embodiments, cup-shaped member 132 a can also include bayonet-stylepins (not shown, but similar to 148, 152) configured to align withcorresponding grooves in head 46 a of probe 38 a to lock the position ofspark head 22 b relative to the probe.

In the embodiment shown, conductors 160 d, 160 e, 160 f extendingthrough a rear portion (opposite outlet cap member 136 a) of cup-shapedmember 132 a, as shown. In this embodiment, central conductor 160 d andperipheral conductors 160 e, 160 f can be molded into sidewall 120 asuch that grommets and the like are not necessary to seal the interfacebetween the sidewall and the conductors. In the embodiment shown, acentral conductor 160 d serves as a ground to corresponding centerelectrodes 100 d-1 and 100 d-2, which are also in electricalcommunication with each other. Peripheral conductors 160 e, 160 f are incommunication with peripheral electrodes 100 e, 100 f to generate sparksacross the spark gap between electrodes 100 d-1 and 100 e, and betweenelectrodes 100 d-2 and 100 f. It should be understood that while twospark gaps are shown, any number of spark gaps may be used, and may belimited only by the spacing and size of the spark gaps. For example,other embodiments include 3, 4, 5, 6, 7, 8, 9, 10, or even more sparkgaps.

In the embodiment shown, central electrodes 100 d-1 and 100 d-2 arecarried by, and may be unitary with, an elongated member 172 extendinginto chamber 124 a toward cap member 136 a from sidewall 120 a. In thisembodiment, member 172 is mounted to a hinge 176 (which is fixedrelative to sidewall 120 a) to permit the distal end of the member(adjacent electrodes 100 d-1, 100 d-2 to pivot back and forth betweenelectrodes 100 e and 100 f, as indicated by arrows 180. In theembodiment shown, the distal portion of member 172 is biased towardelectrode 100 e by spring arms 184. In this embodiment, spring arms 184are configured to position electrode 100 d-1 at an initial spark gapdistance from electrode 100 e. Upon application of an electricalpotential (e.g., via a pulse-generation system, as described elsewherein this disclosure) across electrodes 100 d-1 and 100 e, a spark willarc between these two electrodes to release an electric pulse tovaporize liquid between these two electrodes. The expansion of vaporbetween these two electrodes drives member 172 and electrode 100 d-2downward toward electrode 100 f. During the period of time in whichmember 172 travels downward, the pulse-generation system can re-chargeand apply an electric potential between electrodes 100 d-2 and 100 f,such that when the distance between electrodes 100 d-2 and 100 f becomessmall enough, a spark will arc between these two electrodes to releasethe electric pulse to vaporize liquid between these two electrodes. Theexpansion of vapor between electrodes 100 d-2 and 100 f then drivesmember 172 and electrode 100 d-1 upward toward electrode 100 e. Duringthe period of time in which member 172 travels upward, thepulse-generation system can re-charge and apply an electric potentialbetween electrodes 100 d-1 and 100 e, such that when the distancebetween electrodes 100 d-1 and 100 e becomes small enough, a spark willarc between these two electrodes to release the electric pulse andvaporize liquid between these two electrodes, causing the cycle to beginagain. In this way, member 172 oscillates between electrodes 100 e and100 f until the electric potential ceases to be applied to theelectrodes.

The exposure to high-rate and high-energy electric pulses, especially inliquid, subjects the electrodes to rapid oxidation, erosion, and/orother deterioration that can vary the spark gap distance betweenelectrodes if the electrodes are held in fixed positions (e.g.,requiring electrodes to be replaced and/or adjusted). However, in theembodiment of FIG. 2B, the pivoting of member 172 and electrodes 100d-1, 100 d-2 between electrodes 100 e and 100 f effectively adjusts thespark gap for each spark. In particular, the distance between electrodesat which current arcs between the electrodes is a function of electrodematerial and electric potential. As such, once the nearest surfaces(even if eroded) of adjacent electrodes (e.g., 100 d-1 and 100 e) reacha spark gap distance for a given embodiment, a spark is generatedbetween the electrodes. As such, member 172 is configured to self-adjustthe respective spark gaps between electrodes 100 d-1 and 100 e, andbetween electrodes 100 d-2 and 100 f.

Another example of an advantage of the present movable electrodes, as inFIG. 4B, is that multiple coils are not required as long as theelectrodes are positioned such that only one pair of electrodes iswithin arcing distance at any given time, and such a single coil or coilsystem is configured to recharge in less time than it takes for member172 to pivot from one electrode to the next. For example, in theembodiment of FIG. 4B, an electric potential may simultaneously beapplied to electrodes 100 e and 100 f with electrodes 100 d-1 and 100d-2 serving as a common ground, with the electric potential such that aspark will only arc between electrodes 100 d-1 and 100 e when member 172is pivoted upward relative to horizontal (in the orientation shown), andwill only arc between electrodes 100 d-2 and 100 f when member 172 ispivoted downward relative to horizontal. As such, as member 172 pivotsupward and downward as described above, a single coil or coil system canbe connected to both of peripheral electrodes 100 e, 100 f andalternately discharged through each of the peripheral electrodes. Insuch embodiments, the pulse rate can be adjusted by selecting thephysical properties of member 172 and spring arms 184. For example, theproperties (e.g., mass, stiffness, cross-sectional shape and area,length, and/or the like) of member 172 and the properties (e.g., springconstant, shape, length, and/or the like) of spring arms 184 can bevaried to adjust a resonant frequency of the system, and thereby thepulse rate of the spark head or module 22 b. Similarly, the viscosity ofliquid 128 a may be selected or adjusted (e.g., increased to reduce thespeed of travel of arm 184, or decreased to increase the speed of travelof arm 184).

Another example of an advantage of the present movable electrodes, as inFIG. 4B, is that properties (e.g., shape, cross-sectional area, depth,and the like) of the electrodes can be configured to achieve a knowneffective or useful life for the spark head (e.g., one 30-minutetreatment) such that spark head 22 b is inoperative or of limitedeffectiveness after that designated useful life. Such a feature can beuseful to ensure that the spark head is disposed of after a singletreatment, such as, for example, to ensure that a new, sterile sparkhead is used for each patient or area treated to minimize potentialcross-contamination between patients or areas treated.

FIG. 4C depicts an enlarged cutaway side view of a third embodiment of aremovable spark head or module 22 c. Spark head 22 c is substantiallysimilar to spark head 22 b, except as noted below, and similar referencenumerals are therefore used to designate structures of spark head 22 cthat are similar to corresponding structures of spark head 22 b. Theprimary difference relative to spark head 22 b is that spark head 22 cincludes a beam 172 a that does not have a hinge, such that flexing ofthe beam itself provides the movement of electrodes 100 d-1 and 100 d-2in the up and down directions indicated by arrows 180, as describedabove for spark head 22 b. In this embodiment, the resonant frequency ofspark head 22 c is especially dependent on the physical properties(e.g., mass, stiffness, cross-sectional shape and area, length, and/orthe like) of beam 172 a. As described for spring arms 184 of spark head22 b, beam 172 a is configured to be biased toward electrode 100 e, asshown, such that electrode 100 d-1 is initially positioned at an initialspark gap distance from electrode 100 e. The function of spark head 22 cis similar to the function of spark head 22 b, with the exception thatbeam 172 a itself bends and provides some resistance to movement suchthat hinge 176 and spring arms 184 are unnecessary.

In the embodiment shown, spark head 22 b also includes liquid connectorsor ports 188, 192 via which liquid can be circulated through sparkchamber 124 b. In the embodiment shown, a proximal end 196 of spark head22 b serves as a combined connection with two lumens for liquid(connectors or ports 188, 192) and two or more (e.g., three, as shown)electrical conductors (connectors 160 d, 160 e, 160 f). In suchembodiments, the combined connection of proximal end 196 can be coupled(directly or via a probe or handpiece) to a combined tether or cablehaving two liquid lumens (corresponding to connectors or ports 188,192), and two or more electrical conductors (e.g., a first electricalconductor for connecting to connector 160 d and a second electricalconductor for connecting to both peripheral connectors 160 e, 160 f).Such a combined tether or cable can couple the spark head (e.g., and aprobe or handpiece to which the spark head is coupled) to apulse-generation system having a liquid reservoir and pump such that thepump can circulate liquid between the reservoir and the spark chamber.In some embodiments, cap member 136 a is omitted such that connectors orports 188, 192 can permit liquid to be circulated through a largerchamber (e.g., 18 a) of a handpiece to which the spark head is coupled.Likewise, a probe or handpiece to which spark head 22 a is configured tobe coupled can include electrical and liquid connectors corresponding tothe respective electrical connectors (160 d, 160 e, 160 f) and ports(188, 192) of the spark head such that the electrical and liquidconnectors of the spark head are simultaneously connected to therespective electrical and liquid connectors of the probe or handpiece asthe spark module is coupled to the handpiece (e.g., via pressing thespark head and probe together and/or a twisting or rotating the sparkhead relative probe).

In the present embodiments, a pulse rate of a few Hz to many KHz (e.g.,up to 5 MHz) may be employed. Because the fatiguing event produced by aplurality of pulses, or shockwaves, is generally cumulative at higherpulse rates, treatment time may be significantly reduced by using manymoderately-powered shockwaves in rapid succession rather than a fewhigher powered shockwaves spaced by long durations of rest. As notedabove, at least some of the present embodiments (e.g., those withmultiple spark gaps) enable electro-hydraulic generation of shockwavesat higher rates. For example, FIG. 5A depicts a timing diagram 200enlarged to show two sequences of voltage pulses 204, 208 applied to theelectrodes of the present embodiments with a delay period 212 inbetween, and FIG. 5B depicts a timing diagram 216 showing a greaternumber of voltage pulses applied to the electrodes of the presentembodiments.

In additional embodiments that are similar to any of spark head 22 a, 22b, 22 c, a portion of the respective sidewall (120, 120 a, 120 b) may beomitted such that the respective spark chamber (124, 124 a, 124 b) isalso omitted or left open such that liquid in a larger chamber (e.g., 18or 18 a) of a corresponding handpiece can freely circulate between theelectrodes. In such embodiments, the spark chamber (e.g., sidewall 120,120 a, 120 b can include liquid connectors or liquid may circulatethrough liquid ports that are independent of spark chamber (e.g., asdepicted in FIG. 4).

A series of events (sparks) initiated by a plurality of bursts or groups204 and 208 delivered with the present systems and apparatuses cancomprise a higher pulse rate (PR) that can reduce treatment timerelative to lower PRs which may need to be applied over many minutes.The embodiments can be used to deliver shockwaves at the desired pulserate.

FIG. 6 depicts a schematic diagram of one embodiment 400 of apulse-generation system for use in or with some embodiments of thepresent systems. In the embodiment shown, circuit 400 comprises aplurality of charge storage/discharge circuits each with a magneticstorage or induction type coil 404 a, 404 b, 404 c (e.g., similar tothose used in automotive ignition systems). As illustrated, each ofcoils 404 a, 404 b, 404 c, may be grounded via a resistor 408 a, 408 b,408 c to limit the current permitted to flow through each coil, similarto certain aspects of automotive ignition systems. Resistors 408 a, 408b, 408 c can each comprise dedicated resistors, or the length andproperties of the coil itself may be selected to provide a desired levelof resistance. The use of components of the type used automotiveignition systems may reduce costs and improve safety relative to customcomponents. In the embodiment shown, circuit 400 includes a spark head22 b that is similar to spark head 22 a with the exceptions that sparkhead 22 b includes three spark gaps 412 a, 412 b, 412 c instead of two,and that each of the three spark gaps is defined by a separate pair ofelectrodes rather than a common electrode (e.g., 100 a) cooperating withmultiple peripheral electrodes. It should be understood that the presentcircuits may be coupled to peripheral electrodes 100 b, 100 c of sparkhead 22 a to generate sparks across the spark gaps defined with commonelectrode 22 a, as shown in FIG. 4A. In the embodiment shown, eachcircuit is configured to function similarly. For example, coil 404 a isconfigured to collect and store a current for a short duration suchthat, when the circuit is broken at switch 420 a, the magnetic field ofthe coil collapses and generates a so-called electromotive force, orEMF, that results in a rapid discharge of capacitor 424 a across sparkgap 412 a.

The RL or Resistor-Inductance time constant of coil 404 a—which may beaffected by factors such as the size and inductive reactance of thecoil, the resistance of the coil windings, and other factors—generallycorresponds to the time it takes to overcome the resistance of the wiresof the coil and the time to build up the magnetic field of the coil,followed by a discharge which is controlled again by the time it takesfor the magnetic field to collapse and the energy to be released throughand overcome the resistance of the circuit. This RL time constantgenerally determines the maximum charge-discharge cycle rate of thecoil. If the charge-discharge cycle is too fast, the available currentin the coil may be too low and the resulting spark impulse weak. The useof multiple coils can overcome this limitation by firing multiple coilsin rapid succession for each pulse group (e.g., 204, 208 as illustratedin FIG. 5A). For example, two coils can double the practicalcharge-discharge rate by doubling the (combined) current and resultingspark impulse, and three (as shown) can effectively triple the effectivecharge-discharge rate. When using multiple spark gaps, timing can bevery important to proper generation of spark impulses and resultingliquid vaporization and shockwaves. As such, a controller (e.g.,microcontroller, processer, FPGA, and/or the like) may be coupled toeach of control points 428 a, 428 b, 428 c to control the timing of theopening of switches 420 a, 420 b, 420 c and resulting discharge ofcapacitors 424 a, 424 b, 424 c and generation of shockwaves.

FIG. 7 depicts a block diagram of an embodiment 500 of a radio-frequency(RF) powered acoustic shockwave generation system. In the embodimentshown, system 500 comprises a nonlinear medium 504 (e.g., as inacoustic-delay chamber 58 or nonlinear member described above) thatprovides an acoustic path to from a transducer 512 to target tissue 508to produce practical harmonic or acoustic energy (e.g., shockwaves). Inthe embodiment shown, transducer 512 is powered and controlled throughbandpass filter and tuner 516, RF power amplifier 520, and controlswitch 524. The system is configured such that actuation of switch 524activates a pulse generator 528 to produce timed RF pulses that driveamplifier 520 in a predetermined fashion. A typical driving waveform,for example, may comprise a sine wave burst (e.g., multiple sine wavesin rapid succession). For example, in some embodiments, a typical burstmay have a burst length of 10 milliseconds and comprise sine waveshaving a period duration of 0.1 (frequency of 100 MHz) to 100microseconds (frequency of 10 Hz).

FIGS. 8A-8B and 9 depict two different spark chamber housings. Theembodiments of FIGS. 8A-8B depict one embodiment of a spark chamberhousing. Housing 600 is similar in some respects to the portion ofhousing 14 a that defines head 46 a of probe 38 a (FIG. 4). For example,housing 600 includes fittings 604, 608 to permit liquid to be circulatedthrough spark chamber 612. In the embodiment shown, housing 600 includeselectrode supports 616 and 620 through which electrodes 624 can beinserted to define a spark gap 628 (e.g., of 0.127 mm or 0.005 inches inthe experiments described below). However, housing 600 has an ellipticalinner surface shaped to reflect the shockwaves that initially travelbackwards from the spark gap into the wall. Doing so has the advantageof producing, for each shockwave generated at the spark gap, a first orprimary shockwave that propagates from the spark gap to outlet 640,followed by a secondary shockwave that propagates first to theelliptical inner wall and is then reflected back to outlet 640.

In this embodiment, supports 616 and 620 are not aligned with (rotatedapproximately 30 degrees around chamber 612 relative to) fittings 604,608. In the embodiment shown, housing 600 has a hemispherical shape andelectrodes 624 are positioned such that an angle 632 between a centralaxis 636 through the center of shockwave outlet 640 and a perimeter 644of chamber 612 is about 57 degrees. Other embodiments can be configuredto limit this angular sweep and thereby direct the sound waves and/orshockwaves through a smaller outlet. For example, FIG. 9 depicts across-sectional view of a second embodiment of a spark chamber housing.Housing 600 a is similar to housing 600, with the exception thatfittings 604 a, 608 a are rotated 90 degrees relative to support 620 a.Housing 600 a also differs in that chamber 612 a includes ahemispherical rear or proximal portion and a frusto-conical forward ordistal portion. In this embodiment, electrodes 624 a are positioned suchthat an angle 632 a between a central axis 636 a through the center ofshockwave outlet 640 a and a perimeter 644 a of chamber 612 a is about19 degrees.

FIG. 10 depicts a schematic diagram of an electric circuit for aprototyped pulse-generation system used with the spark chamber housingof FIGS. 8A-8B. The schematic includes symbols known in the art, and isconfigured to achieve pulse-generation functionality similar to thatdescribed above. The depicted circuit is capable of operating in therelaxation discharge mode with embodiments of the present shockwaveheads (e.g., 46, 46 a, etc.). As shown, the circuit comprises a 110Valternating current (AC) power source, an on-off switch, a timer(“control block”), a step-up transformer that has a 3 kV or 3000Vsecondary voltage. The secondary AC voltage is rectified by a pair ofhigh voltage rectifiers in full wave configuration. These rectifierscharge a pair of oppositely polarized 25 mF capacitors that are eachprotected by a pair of resistors (100 kΩ and 25 kΩ) in parallel, all ofwhich together temporarily store the high-voltage energy. When theimpedance of the shockwave chamber is low and the voltage charge ishigh, a discharge begins, aided by ionization switches, which are largespark gaps that conduct when the threshold voltage is achieved. Apositive and a negative voltage flow to each of the electrodes so thepotential between the electrodes can be up to about 6 kV or 6000 V. Theresulting spark between the electrodes results in vaporization of aportion of the liquid into a rapidly-expanding gas bubble, whichgenerates a shockwave. During the spark, the capacitors discharge andbecome ready for recharge by the transformer and rectifiers. In theexperiments described below, the discharge was about 30 Hz, regulatedonly by the natural rate of charge and discharge—hence the term“relaxation oscillation.” In other embodiments, the discharge rate canbe higher (e.g., as high as 100 Hz), such as for the multi-gapconfiguration of FIG. 6.

A further embodiment 38 b of the present (e.g., handheld) probes for usewith some method embodiments are depicted in FIGS. 11-13C. Probe 38 b issimilar in some respects to probes 38 and 38 a, and the differences aretherefore primarily described here. In this embodiment, probe 38 bcomprises: a housing 14 b defining a chamber 18 b and a shockwave outlet20 b; a liquid disposed in chamber 18 b; a plurality of electrodes(e.g., in spark head or module 22 d) configured to be disposed in thechamber to define one or more spark gaps; and is configured to becoupled to a pulse-generation system (e.g., system 26 of FIG. 2)configured to apply voltage pulses to the electrodes at a rate of 10 Hzto 1000 Hz or at a rate of 10 Hz to 100 Hz.

In the embodiment shown, spark head 22 d includes a housing 120 d and aplurality of electrodes 100 g that define a spark gap. In thisembodiment, probe 38 b is configured to permit liquid to be circulatedthrough chamber 18 b via liquid connectors or ports 112 b and 116 b, oneof which is coupled to spark head 22 d and the other of which is coupledto housing 14 b, as shown. In this embodiment, housing 14 b isconfigured to receive spark head 22 d, as shown, such that housing 14 band housing 120 d cooperate to define chamber 18 b (e.g., such thatspark head 22 d and housing 14 b include a complementary parabolicsurfaces that cooperate to define the chamber). In this embodiment,housing 14 b and spark head 22 d includes acoustically-reflective liners700, 704 that cover their respective surfaces that cooperate to definechamber 18 b. In this embodiment, housing 120 d of spark head 22 dincludes a channel 188 b (e.g., along a central longitudinal axis ofspark head 22 d) extending between liquid connector 112 b and chamber 18b and aligned with the spark gap between electrodes 100 g such thatcirculating water will flow in close proximity and/or through the sparkgap. In the embodiment shown, housing 14 b includes a channel 192 bextending between connection 116 b and chamber 18 b. In this embodiment,housing 120 d includes a groove 708 configured to receive a resilientgasket or O-ring 140 a to seal the interface between spark head 22 d andhousing 14 b, and housing 14 b includes a groove 712 configured toreceive a resilient gasket or O-ring 140 b to seal the interface betweenhousing 14 b and cap member 136 b when cap member 136 b is secured tohousing 14 b by ring 716 and retaining collar 144 b.

In the embodiment shown, electrodes 100 g each includes a flat barportion 724 and a perpendicular cylindrical portion 728 (e.g.,comprising tungsten for durability) in electrical communication (e.g.,unitary with) bar portion 724 such that cylindrical portion 728 canextend through a corresponding opening 732 in spark head 22 d intochamber 18 b, as shown. In some embodiments, part of the sides ofcylindrical portion 728 can be covered with an electrically insulativeand/or resilient material (e.g., shrink wrap) such as, for example, toseal the interface between portion 728 and sidewall 120 b. In thisembodiment, sidewall 120 b also includes longitudinal grooves 733configured to receive bar portions 724 of electrodes 100 g. In theembodiment shown, housing 14 b also includes set screws 736 positionedto align with cylindrical portions 728 of electrodes 100 g when sparkhead 22 d is disposed in housing 14 b, such that set screws 736 can betightened to press cylindrical portions 728 inward to adjust the sparkgap between the cylindrical portions of electrodes 100 g. In someembodiments, spark head 22 d is permanently adhered to housing 14 b;however, in other embodiments, spark head 22 d may be removable fromhousing 14 b such as, for example, to permit replacement of electrodes100 g individually or as part of a new or replacement spark head 22 d.

FIG. 14 depicts a schematic diagram of another embodiment of an electriccircuit for a pulse-generation system. The circuit of FIG. 14 issubstantially similar to the circuit of FIG. 10 with the primaryexception that the circuit of FIG. 14 includes an arrangement oftriggered spark gaps instead of ionization switches, and includescertain components with different properties than correspondingcomponents in the circuit of FIG. 10 (e.g., 200 kΩ resistors instead of100 kΩ resistors). In the circuit of FIG. 14, block “1” corresponds to aprimary controller (e.g., processor) and block “2” corresponds to avoltage timer controller (e.g., oscillator), both of which may becombined in a single unit in some embodiments.

EXPERIMENTAL RESULTS

Experiments were conducted on minipigs to observe effects ofEH-generated shockwaves on adipose tissue.

Example 1: Adipose Tissue Inflammation

A study was undertaken to evaluate the induction of inflammation insubcutaneous fat using high-frequency shockwave. A Gottingen minipig(˜30 Kg) was anesthetized. The mid-ventral sites were prepared byremoving the skin hair here using hair clippers and then razor.High-frequency shockwaves were then applied to the two treatment sites.Following the high frequency shockwave treatment, and 48 hours posttreatment, biopsies were taken of treatment sites using 3 mm circularpunch biopsy instruments. Tissue samples were placed in bufferedformalin for microscopic examination.

The high frequency shockwave treatment protocols are shown in Table 1.The probe had a 30 mm diameter shockwave outlet window and wasconfigured to generate electrohydraulic shockwaves. All five sites thatwere treated using different high frequency shockwave settingsdemonstrated inflammation in the subcutaneous fat. No evidence ofcavitation or thermal damage was noted on any of the tissue in theslides.

Site Total J J/P Hz 4.6 20,700 9.2 25 4.7 41,400 9.2 25 4.8 20,700 6.933 4.9 41,400 6.9 33 4.10 20,700 4.6 50

By way of example, histological evaluations of site 4.6 were conductedon the day of treatment and 2 days post treatment. As noted in Table 1,Site 4.6 was treated using a high frequency shockwave treatment for 90seconds at 9.2 J/p at a rate of 25 Hz. The adipose tissue demonstratedmarked inflammatory cell infiltration two days post treatment indicatingthat inflammation had been induced. Furthermore, there was no evidenceof cavitation, thermal damage or other tissue damage at the treatmentsite.

Example 2: Adipose Tissue Volume Loss

A study was undertaken to evaluate subcutaneous volume loss followingtreatment with high frequency shockwaves. A Gottingen minipig (˜30 Kg)was prepared as described in Example 1. Two separate test sites (1.7,1.8) were treated using high-frequency shockwaves (9.2j/p, 25 Hz, 240seconds). The probe had a 30 mm diameter shockwave outlet window and wasconfigured to generate electrohydraulic shockwaves.

Two weeks following the high frequency shockwave treatment, the amountof post-treatment volume change was assessed utilizing a CanfieldScientific Vectra three-dimensional camera and software. Volumetricpictures of the test sites (1.7, 1.8) were compared to adjacent controlsites (Sites 1.9, 1.10). A loss of volume was indicated from the treatedsites (1.7, 1.8). Furthermore, the skin for both test sites demonstrateddiscoloration of the overlying skin. This is consistent with theappearance skin overlying panniculitis. Thus, the discoloration likelyindicates underlying inflammation.

Example 3: Lipid Crystallization

A study was performed to demonstrate that non-cavitating, non-thermal,high intensity shockwaves when applied to adipose tissue results in thecrystallization of the adipocyte lipids. A Gottingen Minipig (˜30 Kg)was prepared as described in Example 1. Site 1.8 after treatmentdescribed in Example 2 was measured immediately following the highfrequency shockwave treatment. A biopsy was taken of the subcutaneousfat at the treated site. For comparison, a biopsy was taken at anon-treated site. Samples of the biopsied tissues were stored in salineand then prepared for cross-polarized light microscopic examination tosee if evidence of crystal nucleation had occurred. To aid invisualizing crystal nucleation, tissue samples were cooled to allowcrystal growth at the crystal nucleation sites.

Both samples were heated to 45C, and then cooled to OC for 45 minutes.The treated adipose sample had a luminosity of 34 compared to thecontrol adipose sample's luminosity of 32. The bigger the luminosityvalue the brighter the sample which is indicative of more polarizedcrystals. Based on this study, the adipose tissue from high frequencyshockwave treated sites had evidence of significant crystallization whencompared to untreated adipose tissue.

The above specification and examples provide a description of theprocess and use of exemplary embodiments. Although certain embodimentshave been described above with a certain degree of particularity, orwith reference to one or more individual embodiments, those skilled inthe art could make numerous alterations to the disclosed embodimentswithout departing from the scope of this invention. As such, the variousillustrative embodiments of the present methods are not intended to belimited to the particular steps disclosed. Rather, they include allmodifications and alternatives falling within the scope of the claims,and embodiments other than the one shown may include some or all of thefeatures of the depicted embodiment. Further, where appropriate, aspectsof any of the examples described above may be combined with aspects ofany of the other examples described to form further examples havingcomparable or different properties and addressing the same or differentproblems. Similarly, it will be understood that the benefits andadvantages described above may relate to one embodiment or may relate toseveral embodiments.

The claims are not intended to include, and should not be interpreted toinclude, means-plus- or step-plus-function limitations, unless such alimitation is explicitly recited in a given claim using the phrase(s)“means for” or “step for,” respectively.

REFERENCES

-   [1] Manstein, D; Laubach, H; Watanabe, K; Farinelli, W et al.    (2008). “Selective cryolysis: A novel method of non-invasive fat    removal”. Lasers in Surgery and Medicine 40 (9): 595-604.-   [2] Krueger N, Mai S V, Luebberding S, Sadick N S, Cryolipolysis for    noninvasive body contouring: clinical efficacy and patient    satisfaction. Clinical, Cosmetic and Investigational Dermatology,    2014:7-   [3] Ferraro G A, De Francesco F, Cataldo C, Rossano F, Nicoletti G,    D'Andrea F, Synergistic effects of cryolipolysis and shock waves for    noninvasive body contouring. Aesthetic Plast Surg. 2012 June;    36(3):666-7

1. A method of treating a patient comprising: directing a pressure wavegenerating probe to a first treatment area of the patient; and emittinga plurality of pressure waves to the first treatment area at a pulserate of between 15 Hz and 100 Hz, where the pressure wave generatingprobe is configured to emit the plurality of pressure waves each havingan acoustic pressure amplitude between 0.5 to 50 MPa; where theplurality of pressure waves are directed to the first treatment area fora duration substantially between 60 and 240 seconds; where the pluralityof pressure waves are not focused prior to entering into the firsttreatment area of the patient.
 2. The method of claim 1, wherein thefirst treatment area includes an area of subcutaneous fat comprising fatcells having intracellular fat and interstitial space between the fatcells.
 3. The method of claim 2, wherein the plurality of pressure wavesare emitted at a pulse rate of substantially between 20 and 75 Hz. 4.The method of claim 1, further comprising: directing the pressure wavegenerating probe to a second treatment area emitting a plurality ofpressure waves to the second treatment area at a pulse rate ofsubstantially between 15 Hz and 100 Hz; and where the plurality ofpressure waves are directed to the second treatment area for a durationsubstantially between 60 and 240 seconds.
 5. The method of claim 4,wherein the second treatment area includes an area of subcutaneous fatcomprising fat cells having intracellular fat and interstitial spacebetween the fat cells.
 6. The method of claim 5, further comprisingdirecting at least a portion of the plurality of pressure waves to thefirst treatment area and the second treatment area such that delivery ofthe at least a portion of the plurality of pressure waves to the firstand second treatment areas reduces the appearance of cellulite in thetreatment areas.
 7. The method of claim 1, wherein: pressure wavegenerating probe comprises a pressure wave outlet window, where thepressure wave generating probe is configured to emit the plurality ofpressure waves each having an energy density of less than 2.0 mJ per mm²at the pressure wave outlet window, and
 8. The method of claim 7,further comprising applying the plurality of pressure waves to anadipose tissue in the treatment area at: a pulse rate of between 25 and500 HZ; and an energy density of between 0.5 and 2.0 mJ per mm² perpressure wave.
 9. The method of claim 8, where the plurality of pressurewaves emitted by the pressure wave generating probe induce no adiposecell damage when treating the treatment area.
 10. The method of claim 1,where the plurality of pressure waves do not induce transient cavitationin an aqueous solution of the pressure wave generating probe.
 11. Themethod of claim 1, where: the plurality of pressure waves include apressure wave energy of between 0.50 and 7.0 mJ per mm² at the pressurewave outlet window; and the pressure wave outlet window has an area ofbetween 0.5 and 20 mm².
 12. A method of inducing inflammation ofsubcutaneous adipose tissue in a treatment area of a patient, the methodcomprising: directing a pressure wave generating probe to an externaltreatment area of the patient; and emitting a plurality of pulses to thetreatment area, each pulse including a plurality of pressure waves at arate of between 15 Hz and 100 Hz; wherein a time period between pulsesof is substantially between 0.5 to 50 microseconds where the pluralityof pulses are directed to the treatment area for a durationsubstantially between 60 and 240 seconds; where the plurality ofpressure waves are not focused prior to entering into the treatment areaof the patient.
 13. The method of claim 12, where: the pressure wavegenerating probe comprises a pressure wave outlet window, and thepressure wave generating probe is configured to emit the plurality ofpressure waves having between 0.5 and 7.0 mJ per mm² at the pressurewave outlet window.
 14. The method of claim 12, where the plurality ofpulses are applied to the treatment area at a pulse energy of 4.6 Joulesper pulse.
 15. The method of claim 12, where each of the plurality ofpressure waves includes a rise time of less than 20 nanoseconds.
 16. Themethod of claim 12, where the plurality of pressure waves have anacoustic pressure amplitude between 0.5 to 50 MPa.
 17. The method ofclaim 12, where the treatment area is within a depth of 6 cm from asurface of the treatment area, and where the treatment area is a butt,thigh, stomach, waist, upper arm area, or a portion thereof.
 18. Themethod of claim 9, where the plurality of pressure waves emitted fromthe pressure wave generating probe comprise substantially planarpressure waves.
 19. Acoustic shockwave generation system configured toreduce subcutaneous fat in a treatment area, where fat comprises fatcells having intracellular fat and interstitial space between the fatcells, the apparatus comprising: a pressure wave generating probeconfigured to deliver a series of pressure waves to an external area ofthe patient, the pressure wave generating probe comprising: a housingdefining a chamber and a shockwave outlet, the chamber configured to befilled with a liquid; and a plurality of electrodes disposed in thechamber to define one or more spark gaps; where the pressure wavegenerating probe is configured to emit the series of pressure waves at apulse rate of between 15 Hz and 1000 Hz; where the pressure wavegenerating probe is configured to emit the plurality of pressure waveseach having an acoustic pressure amplitude between 0.5 to 50 MPa; wherethe plurality of pressure waves are not focused prior to entering intothe first treatment area of the patient.
 20. The system of claim 19,where the pressure wave generating probe is configured to emit theplurality of pressure waves at an energy density of between 0.5 and 7.0mJ per mm² at the shockwave outlet and induce no transient cavitationbubbles in a water-based medium, and where a pressure wave outlet windowassociated with the shockwave outlet has an area of 0.5 cm² to 20 cm².